Our invention relates to a drive for a multicolor sheet-fed rotary press and, more particularly, for a multicolor sheet-fed rotary press with a plurality of press mechanisms with press cylinders.
A drive for a multicolor sheet-fed rotary press is known, in which torsion spring-rods are mounted on axle journals of the press cylinder for power bypassing and reliable performance of a permanent gear unit(WP B41F 319 549.3). This method has the disadvantage that during flow of power from the main drive shaft to the press cylinder a clutch bypassing a torsion spring-rod must be provided, in order to, e.g. in the slow-speed and inching modes of operation, drive the press cylinder by the main drive shaft while the drive shaft is rigidly connected to the press cylinder. In machines with more than two press mechanisms the clutches are disadvantageously large and are not very easily accessible. Moreover additional bearing forces occur on the press cylinder and/or on the transfer drum in the inching, slow-speed, braking and starting modes of operation, when the coupling is mounted on the gear stage in front of the press cylinder. This solution is also comparatively expensive, since a clutch must be provided for each driven location in the press.